Power roof ventilator



June 20, 1961 J. JENN ETAL 2,988,981

POWER ROOF VENTILATOR Filed March 12, 1958 INVENTORS. Zoo/3 JI JAN/Y.JflMES W. Sewn 1:2.

United States t nt "ice 2,988,981 POWER ROOF VENTILATOR Louis J. Jen andJames W. Schwier, Indianapolis, Ind.,

assignors to Jenn Air Products Company, Inc., Indianapolis, 'Ind., acorporation Filed Mar. 12, 1958, Ser. No. 720,854

1 Claim. (Cl. 98-43) I This invention relates generally to power roofventilators, and in particular to a ventilator of this type arranged todischarge air at a maximum height above roof level with a minimumover-all extension thereabove.

Power roof ventilators are conventionally mounted upon a preconstructedcurb and are arranged to extend upwardly from the roof level, it beingdesirable to discharge air from the ventilator at a substantial heightabove the roof level. This desirable feature is opposed by the furtherrequirement that the height of extension above the roof level of theventilator unit be maintained at a minimum. In the design of ventilatorsof the type referred to it is further desirable to provide a means forcontrolling the angular movement of the air flowing through theventilator body prior to its; introduction into the impeller, or otherair moving means proper. Control of this characteristic of the enteringair stream is conventionally referred to as control of the prerotationofthe air flowing through the ventilator. In the design of ventilators,particularly power operated roof ventilators, it is also desirable toisolate and prevent transmission of vibration from the air moving meansand other movable parts to the exterior frame or body of the ventilator.

The primary object of the present invention, therefore, is to provide apower roof ventilator having the air moving means mounted at the top ofthe unit, above the supporting and driving means, thereby allowing theair to be discharged at a substantial distance above the roof levelwhile maintaining a relatively low over-all ventiator unit height.

A further object of the present invention is to provide a power roofventilator having a cap or rain cover supported by a grille which alsoacts as a guard against entry of birds or rodents into the ventilator.

It is a further object of the present invention to provide a power roofventilator which incorporates a plurality of vanes extending transverseto the air path through the ventilator body and providing a mountingmeans for a driving device such -as an electric motor, the vanes therebyserving the dual function of providing a support and also controllingthe prerotation of the air flowing through the ventilator unit.

A further object of the present invention is to provide a power roofventilator in which the air moving'means and all other moving parts aresuspended on a frame or body by means of a rubber-in-shear mounting,with metal to metal contact between the moving parts and the ventilatorbody being thereby eliminated.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claim:

FIG. 1 is a side sectional view of a vventilator embodying the presentinvention.

FIG. 2 is an enlarged, fragmentary view taken generally along the line22 of FIG. 1.

FIG. 3 is a fragmentary, sectional view of a modified form of theventilator.

Referring initially to FIGS. 1 and 2, there is shown at a preconstructedcurb extending upwardly from the roof level indicated at 11. Overlyingthe annular curb is a support ring -12 which carries a metal member 1'3,having a stepped configuration in cross section. The upstanding marginalflange 14 of the member 13 has Patented June 20,1961

mounted thereon a steel band 16 by means of bolts 17. The bolts alsoserve to secure to the outer face of the band a cylindrical shell 18which may be formed of aluminum or similar'corrosion resistant metal.

Welded to the band at spaced intervals therearound are support posts 19which, as may best be seen in FIG. 2, are L-shaped in cross section.Adjacent their upper ends the support posts are bolted to the shell 18by means of bolts 21.

Referring now principally to FIG. 2, it may be seen that each of theposts 19 has secured thereto by means of bolts 22 a facing plate 23. Thesurface of the plate, between the bolts 22 has bonded thereto a rubbercushioning block 24. The block may be formed of cushioning rubber orsimilar vibration insulating material. The opposite face of the rubberblock has bonded thereto a facing plate 26 having threaded studs 27extending therefrom and through appropriately positioned apertures inradially extending vanes 28. Nuts 29 threaded on the studs serve to lockthe vanes to the facing plate 26. It will be understood that any desirednumber of supporting posts and radially extending vanes may be provided,only two being visible in FIG. 1.

The inner ends of the vanes are welded, or otherwise suitably secured toa tubular column 31 which extends upwardly through the ventilator andprotrudes beyond the upper margin of the exterior shell 18. At each ofits ends the column carries bearing members 32 which journal a driveshaft 33, thrust washers 34 fixed to the shaft serving to retain theshaft in position longitudinally. At its upper end the shaft carriesmounted for rotation thereon a hub casting 36. By means of rivets 37 thehub supports an air impeller having a body section 38 from whichradially extend a series of blades or vanes 39.

At its lower end the drive shaft has mounted thereon a pulley 41connected by means of a V-belt 42 to a pulley 43. The pulley 43 ismounted on the output shaft of an electric motor 44. The motor ismounted by means of bolts 46 on one of the vanes 28. The bolts extendthrough appropriate slots 47 in the vanes to provide for belt tensionregulating adjustment of the position of the electric motor.

Mounted on the upper margin of the shell 18 is a plate 48 having acentral aperture defined by an upturned flange 49 providing an inletorifice for the impeller. The connection between the shell and the plate48 is provided by bolts 51 which also serve to secure to the shell asuitably formed, annular grille 52. The outer margin of the grille issecured by means of bolts 53 to a concavo-convex cover or rain cap 54which overlies and encircles the impeller.

From the foregoing it will be evident that the support posts and theouter shell attached thereto provide a tubular exterior frame. Theradially extending vanes, having a vibration insulating mounting,support the drive shaft in a position such that its axis coincides withthe longitudinal axis of the ventilator body. One of the vanes serves asa mounting means for the electric motor driving the impeller. The motorand impeller together with other moving parts of the ventilator are thussuspended on and vibrationally insulated from the ventilator frame orbody.

In operation, the motor rotates the impeller to draw air past theradially extending vanes, through the inlet orifice, and discharges theair through the annular discharge opening provided between the cap andthe upper margin of the ventilator body.

By appropriately tilting or positioning the major plane of the vanes itwill be evident that the incoming air flowing through the ventilatorbody may be given an angular prerotation either in the same direction asor against the direction of rotation of the impeller, or the vanes maybe maintained aligned with the longitudinal axis of the ventilator body,as shown in FIG. 1, to thereby reduce rotation of the incoming air. Thevanes 28 thus not only provide a mounting for the drive shaft and .themotor, but .in addition also 'provide a means for controlling theprerotation of the air flowing through the ventilator unit.

The annular grille 52 supports the overlying cap and also performs theadditional function of providing a guard for 'the air discharge opening.The support of the motor and the motion transmission means for the driveshaft below the impeller permits the air discharge opening of theventilator unit to be located at a maximum height above the roof levelwith a minimum over-all extension of the ventilator'unit above the rooflevel.

Referring now to FIG. 3, there is shown fragmentarily a modified form ofthe ventilator utilizing a fan rather than a centrifugal impeller. Inthis form of the ventilator a shroud 48a is mounted on theouter shell18a and encloses a fan having blades 39a, the fan being mounted on theupper end of the drive shaft 33a for rotation thereby. The cap or raincover 54a has a concavo-convex configuration similar to the cap referredto with reference to FIG. 1, but is additionally provided with adepending cup-shaped member 56 whose curved inner surface serves todirect the air to the discharge opening with a minimum of turbulence.The grille 52a serves to support the overlying cap and also to provide aguard for the discharge opening in identical fashion to the grilledescribed with reference to FIG, 1.

The operation of this modified form of the ventilator is identical tothat of the ventilator described previously and differs from it only inthe provision of the air directing surfaces necessary when the airmoving means takes the form of a rotary fan.

While the invention has been disclosed and described in some detail inthe drawings and foregoing description, they are to be considered asillustrative and not restrictive in character, as other modificationsmay readily suggest themselves to persons skilled in this art and withinthe broad scope of the invention, reference being had to the appendedclaim.

The invention claimed is:

A power ventilator comprising a tubular body adapted to be mountedupright on a roof surface, a central shaft disposed longitudinallyWithin said body, a plurality of radial vanes within and secured to saidbody and supporting said shaft, an annular plate mounted on said body atthe top thereof and defining an air inlet orifice through which saidshaft extends, air moving means mounted for rotation on the portion ofsaid shaft extending beyond said orifice and adapted to draw air throughsaid body and past said inlet orifice, a concavo-convex cap overlyingsaid air moving means and having its margins laterally spaced from saidbody to provide an annular air discharge opening, .power means fordriving said shaft supported on one of said vanes, said vanes beinggenerally aligned with the direction of air movement through said bodyto thereby control the prerotation of air entering said inlet orifice.

References Cited inthe file of this patent UNITED STATES PATENTS2,157,609 Hopkins May 9, 1939 2,322,302 Martinson June.22, 19432,728,541 Hansel Dec. 27, 1955 2,735,611 McLean Feb. 21, 1956 2,868,105Knutson et al. Jan. 13, 1959 2,875,678 Shepherd Mar. ,3, 1959

